Field of the Invention
The present disclosure generally relates to image processing and, more particularly, to an image processing apparatus, an image processing method, a recording medium, and to processing for synthesizing a plurality of images to generate a panoramic image for stereo viewing.
Description of the Related Art
A technique of taking a stereo panoramic image is demanded in order to acquire a video image with a high sense of reality. As the technique therefor, there is a method for taking a stereo panoramic image by using a plurality of cameras (WO12/002046, and Yan Tao, “Seamless Stitching of Stereo Images for Generating Infinite Panoramas”, “Proceedings of the 19th ACM Symposium on Virtual Reality Software and Technology”, Singapore, ACM, 2013, 251-258 (hereinafter, represented as Yan Tao)). WO12/002046 describes that a panoramic image for left eye is generated by stitching a plurality of images for left eye taken by rotating a set of stereo cameras, and a panoramic image for right eye is generated by stitching images for right eye. Yan Tao describes that positions of seams between a plurality of images for left eye and a plurality of images for right eye at a time of stitching are decided by using an evaluation function in which a disparity amount between the images for left eye and the images for right eye is taken into consideration.
In a technique described in WO12/002046, the seam positions between the images for left eye and the images for right eye at a time of stitching are decided in advance, and difference between disparities caused by variation of a distance to an object is not considered. Therefore, at a time of viewing a stereo image, seams are generated at different positions of the images for left eye and the images for right eye in a scene. In this case, there is a problem that a phenomenon called binocular rivalry that feeling of discomfort or unpleasantness is caused when a video image in which positional relationships are inconsistent or different between the right eye and the left eye is presented occurs near the seams of the images. On the other hand, in a technique of Yan Tao, by using the evaluation function with consideration of a disparity of images when deciding a seam of the images, it is set so that the seams are easily set at close positions in the images for left eye and the images for right in a scene. However, only by adding a term in which the disparity of the images is considered to the evaluation function, the seam positions are not always matched between the right and left images because of other terms included in the evaluation function, and binocular rivalry may occur during viewing. Thus, in the technique, when images for left eye and images for right eye which are used for stereo viewing are generated by image stitching, binocular rivalry caused by a difference of seam positions of the images is suppressed.